膜生物反应器污泥内源消化及SMP变化

膜生物反应器（MBR）中高污泥浓度和低F/M会导致部分微生物长期处于贫营养状态下，因此采用污泥内源消化试验模拟MBR中实际存在的贫营养现象。比较了好氧消化（AD）和好氧/缺氧消化（A/A/D）2种模式对于A²O+MBR工艺剩余污泥的内源消化效果及SMP的变化。研究结果表明，常温条件下A/A/D 20 d MLVSS的去除率可达到50%，AD为42%，缺氧段的引入促进了有机物和营养物质等的释放和去除，SMP浓度均呈现出显著降低而后缓慢增长并趋于稳定的趋势。EEM光谱分析表明，SMP中不同的荧光物质在内源消化过程中呈现出不同的变化规律。GPC分析认为，内源消化过程中SMP的分子量范围逐渐扩大，小分子量有机物呈增长趋势，A/A/D对SMP的降解比AD更为有效。

SMP variation during endogenous digestion of activated sludge from a MBR process

Under the circumstance of high sludge concentration and low F/M ratio,part of the microorganisms will suffer the shortage of nutrition in the MBRs. The experiment of activated sludge endogenous digestion was conducted to simulate the real existed phenomenon of nutrition shortage. Endogenous digestion performance of sludge taken for a practical A²O+MBR process and variations of soluble microbial products (SMP) were compared between two methods adopting aerobic digestion (AD) and aerobic/anoxic digestion (A/A/D). The results indicated that MLVSS removal could reach 50% and 42% after 20 days' aerobic/anoxic and aerobic digestion,respectively,which meant that A/A/D improved the release and removal of organic substances and nutrients. The concentration of SMP firstly decreased obviously and then increased gradually until reaching a steady level. EEM spectra showed that different fluorescent substances of SMP demonstrated different variation tendency. GPC showed that the range of molecular weight distribution of SMP increased with digestion time,and the amount of organic matter with low molecular weight significantly improved,which indicated that A/A/D was more efficient for the degradation of SMP.